[RESEND] [PATCH v2 1/2] arm: devtree: Set system_rev from DT revision

Rob Herring robherring2 at gmail.com
Mon Jul 6 10:30:15 PDT 2015


On Mon, Jul 6, 2015 at 11:20 AM, Pali Rohár <pali.rohar at gmail.com> wrote:
> On Monday 06 July 2015 17:22:58 Rob Herring wrote:
>> On Mon, Jul 6, 2015 at 8:12 AM, Pali Rohár <pali.rohar at gmail.com> wrote:
>> > On Monday 06 July 2015 14:31:27 Tony Lindgren wrote:
>> >> * Pali Rohár <pali.rohar at gmail.com> [150706 05:25]:
>> >> > into which file should I put documentation about new DT
>> >> > properties?
>> >>
>> >> If it's Linux generic like linux,revision, then how about
>> >> Documentation/devicetree/bindings/revision.txt?
>> >>
>> >> For the ATAGs, Documentation/devicetree/bindings/arm/atag.txt?
>> >>
>> >> Regards,
>> >>
>> >> Tony
>> >
>> > Hm... now I'm thinking into which DT field should I put atags and
>> > revision. In previous emails you wrote to use "linux,atags", now
>> > "arm,atags"? And put them into root node? Or other?
>> >
>> > In arch/arm/boot/compressed/atags_to_fdt.c code I see that most
>> > atag properties are converted into "/chosen" node in DT...
>> >
>> > So what do you prefer for "revision" and what for "atags"?
>> >
>> > Some mentioned examples:
>> >
>> > "/revision"
>>
>> This one. This is a top level h/w property.
>>
>> > "/chosen/revision"
>> > "/linux,revision"
>> > "/chosen/linux,revision"
>> > ...
>> >
>> > "/atags"
>> > "/chosen/atags"
>> > "/linux,atags"
>> > "/chosen/linux,atags"
>>
>> This one. ATAGs are a Linux data struct.
>>
>> Rob
>>
>
> Ok, and how read that property "/chosen/linux,atags" in function
> setup_machine_fdt() from file arch/arm/kernel/devtree.c ?
>
> of_get_flat_dt_prop() cannot be used unless somebody get me offset to
> node "/chosen"...

Why can't you get the offset yourself?

However, why does this need to be early? It is only used to populate
/proc, right?

Rob



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